This invention relates, in a first aspect, to the field of containers for transporting and storing three-dimensional dentition models (dental casts and impressions). In a second aspect, the present invention relates to a method of shipping three-dimensional dentition models to a processing facility and for handling the models at the facility.
In dentistry, and particularly in the field of orthodontics, it is frequently necessary to create a “stone” model or cast that is an accurate replica of the hard and soft tissues (i.e, teeth and gums) of a patient's dental arch. The first step in making the stone model is to make a dental impression, using an impression material. Typical impression materials include alginate (irreversible hydrocolloid), agar (reversible hydrocolloid), polysulfide, polyether, and polyvinylsiloxane (PVS). Impression materials are generally transferred to the patient's mouth in an impression tray while the materials are initially fluid and require support. Once the tray is positioned on the patient's dental arch, the materials undergo setting by either a chemical or physical process. After setting, the impression is removed from the patient's mouth, and a stone model may then be prepared, using a dental gypsum material that is initially fluid and that can be poured into the impression, where it hardens to form a rigid replica of the dental arch. This rigid replica is called a cast or a stone.
State-of-the-art processes for the fabrication of orthodontic appliances are directed toward the production of a set of appliances that are custom-made for each individual patient, and that are designed to be used in a pre-defined sequence to move the patient's teeth progressively toward a predetermined final orthodontic arrangement. The fabrication process starts with a dentist making impressions of the upper and lower dental arch. A stone or cast may also be made from the upper and lower impressions, respectively. A “bite registration,” an impression of the upper and lower teeth together as they are mutually registered when the patient bites, is also typically made. For the purpose of the ensuing description, the impressions, the stones, and the bite registration may be collectively referred to as 3-D dentition models. For each patient, the 3-D dentition models (a bite registration and upper and lower dental arch models, the dental arch models being either impressions or stones), are packed by the dentist and shipped to an orthodontic appliance manufacturing facility in a shipping container. The 3-D dentition models are then removed from the shipping container. Impressions and bite registrations (but not stones) must then be disinfected. In some cases the models are then loaded into a specially designed carrier or holder in which they are held while they undergo a scanning procedure, typically by means of a CT scanning device. After scanning, the dentition models are unloaded from the scanning carrier or holder and stored in an archive area. A dentist may also wish to send the stones/impressions and/or bite registration to a lab or other facility for other purposes, such as having a digital image prepared for diagnostic or other uses.
The above process thus entails three separate, labor-intensive steps after receipt of the stones and the bite registration by the appliance manufacturing facility:
1. Removing the dentition models from the shipping container;
2. Loading the dentition models into a scanning carrier or holder before scanning is performed; and
3. Unloading the dentition models from the carrier or holder after the scanning is completed.
In addition, for dentition models that are impressions or bite registrations, a disinfecting step must be performed between the step of removing the dentition models from the container and the step of loading them into a scanning carrier or holder.
It can be seen that the above procedure requires the 3-D dentition models to be manually handled, which is time-consuming, and which can result in increased opportunities for the dentition models to be damaged. It would thus be greatly advantageous to simplify the above procedure and to make it less labor-intensive and thus less costly and time-consuming. It would also be advantageous to reduce the risk of damage to the dentition models from the time of receipt by the manufacturing facility through completion of the scanning procedure.